The method relates to a method for the provision of data via a pilot channel of a radio communication system, especially a mobile radio system, and also to components of such a radio communication system for implementing the method.
A steadily increasing number of different radio communication systems, by way of example only the systems according to the known standards GSM, IS-95, UMTS, CIMA2000, WLAN, WiMAX are mentioned, means that terminals as user terminals are supporting an ever greater number of these systems and/or standards. Because of this, a user using such a terminal is enabled to access communication networks in a variety of ways. Furthermore, operators of radio communication systems are increasingly providing systems with different standards to their customers, which offers the possibility of roaming between these different systems.
All this can, however, lead to the disadvantage that because of the large number of available systems, which also generally operate in different system-specific frequency bands or access physically different resources in another manner, the period for establishing a connection through a terminal is increased. If a user, for example, wants to use a high data rate service, e.g. video streaming, a service of this kind can potentially be provided by different systems. Provided no specific system was selected in advance by the user or his terminal, contact to various systems takes place by the terminal during the establishment of the connection. The terminal in this case preferably attempts to first receive signals from different systems, for example systems of the same operator, and then selects a system suitable for the selected service.
Especially if the terminal is brought into service at a location at which it previously had absolutely no connection to a system and therefore cannot make use of empirical values, for example if the user is using his terminal after flying to a foreign country, there is the added factor of not knowing with which local operator the home operator has made a roaming agreement to enable customers to have reduced connection charges, which creates difficulties or extends the access time. In this case, a local system or local operator is offered to the user several times with the user having to decide whether or not a connection should take place.
To clearly arrange the growing number of systems or access possibilities for users or their terminals, it was proposed in document “Global Pilot Mechanism, Tdoc SMG2 UMTS 52/97, ETSI STC SMG2 UMTS adhoc, 8.-10. April 1997, Lulea, Schweden, p. 1 and 2 amongst others, to introduce a unified global pilot channel (global pilot channel) on a unified frequency channel or unified frequency spectrum. Information on respective locally available radio access technologies (radio access technology indicator) and pointers (spectral pointers) to their spectral position is to be transmitted as access possibilities on a global pilot channel of this kind. Furthermore, a terminal can select a suitable, or supported, radio access technology as an access possibility for establishing a radio interface and also access same. Radio access technologies in this case, for example, mean systems with different standards, such as GSM and UMTS, which operate in different frequency bands. According to the aforementioned document, the transmission of the pilot channel should take place either by the operator himself, who would have to correspondingly also transmit information on competing operators, or else information on a national body, (not specified in more detail), for example a regulating body.
Such a pilot channel, which is also known as a cognitive pilot channel (CPC) or common pilot channel, is therefore a special radio-supported communication channel which announces information data as data on the available radio systems. A pilot channel of this kind is especially proposed for cognitive or reconfigurable radio interface devices, which, e.g. support concepts such as a flexible spectrum management or a dynamic spectrum allocation. Terminals with such reconfigurable radio interface devices are increasingly interesting from the point of view of the very large number of different radio communication systems which can change with respect to a spatially moving terminal, both over time as well as relative to the momentary location. In such cases, it would be impractical and time-consuming for a terminal to scan the radio spectrum for available access possibilities.
From E2R-Project (see) http://e2r2.motlabs.com/), a concept with a cognitive/common pilot channel is known that announces information data regarding available radio systems. However, apart from the general basic concept of a cognitive pilot channel of this kind for announcing information data on available radio systems, and possibly also for providing configuration information or configuration software for enabling the configuration of a reconfigurable radio interface device, no detailed information is given.
From the former European Patent Application EP 05027892.8, a concept with a 3-stage cognitive pilot channel is known which is focused on how the operator organizes a common pilot channel in order to show the use of a spectrum with respect to various radio access technologies, especially of any operators, as access possibilities. However, the given possibilities are also limited.
From DE 199 20 587 C2, a non-generic construction and a continuous updating of a radio field database by measured data, which is recorded during a communication phase, is known, with the mobile station as a terminal being linked to available measured data and this information being linked to locating information and this information then being passed to a suitable interface in a network element belonging to the fixed network infrastructure and being evaluated. Such measured data processed by the radio network infrastructure is held ready by same to be called up, in order to enable a mobile terminal outside of communication phases to also be located. However, no reference to pilot channels can be seen in this case.